update README for next release

Author: maiflai

README.md

@@ -7,7 +7,7 @@ A plugin to enable the use of Scoverage in a gradle Scala project.
 Usage
 -----
 
-You can find instructions on how to apply the plugin at:  http://plugins.gradle.org/plugin/org.scoverage
+You can find instructions on how to apply the plugin at http://plugins.gradle.org/plugin/org.scoverage
 
 ### Available tasks
 
@@ -18,7 +18,7 @@ You can find instructions on how to apply the plugin at:  http://plugins.gradle.
     tasks to run only the desired tests.  For example, to run only the unit tests and no other test
     tasks (e.g., integration tests), you can run `reportTestScoverage`.
 
-2. `aggregateScoverage`: An experimental support for aggregating coverage statistics in composite builds.
+2. `aggregateScoverage`: Aggregates coverage statistics in composite builds.
 
     When applied on a project with sub-projects, the plugin will create the aggregation task `aggregateScoverage`, which
     will first generate reports for each project individually (including the parent project), and will then generate an
@@ -41,7 +41,7 @@ You can find instructions on how to apply the plugin at:  http://plugins.gradle.
 The plugin exposes multiple options that can be configured by setting them in an `scoverage` block within the project's
 build script. These options are as follows:
 
-* `scoverageVersion = <String>` (default `"1.3.1"`): The version of the scoverage scalac plugin. This (gradle) plugin
+* `scoverageVersion = <String>` (default `"1.4.1"`): The version of the scoverage scalac plugin. This (gradle) plugin
 should be compatible with all 1+ versions.
 
 * `scoverageScalaVersion = <String>` (default `"2.12"`): The scala version of the scoverage scalac plugin. This will
@@ -113,6 +113,21 @@ it is possible to only compile the code with the scoverage scalac plugin, thus r
 In order to do so, simply add the arguments `-x compileScala` to the gradle execution.
 For example: `gradle reportScoverage -x compileScala`.
 
+Migration to 4.x
+----------------
+
+* Requires scoverage 1.4.1 or higher (and uses this version by default)
+* Requires application of the plugin to appropriate subprojects. A multi-module project might apply it to all.
+
+```groovy
+plugins {
+    id 'org.scoverage' version '4.0.0' apply false
+}
+allprojects {
+    apply plugin: 'org.scoverage'
+}
+```
+
 Migration to 3.x
 ----------------